What is max pain?

A popular theory, and the measurement it usually escapes

Max pain is the strike at which the largest total value of open options would expire worthless — the price that inflicts the most aggregate loss on option buyers. The theory attached to it is that the index gets drawn toward that strike as expiry approaches, because dealers who are short those options profit if it settles there and hedge in a way that pulls it in.

The mechanism people describe

The plausible half is real: near expiry, dealers long gamma at a heavily-traded strike must sell rallies and buy dips to stay hedged, and that flow does pin price around that strike. This is the wall mechanic and it is measurable.

The implausible half is the leap from "hedging damps movement near a big strike" to "the index is pulled to the single strike that maximises option-holder loss". Those are different claims. The first is about local damping; the second requires a directional magnet, and a magnet needs someone actively pushing.

What we measured

Pinning is a testable, published claim — Golez & Jackwerth (2012) is the standard reference — so we tested it rather than repeating it. We replicated it on 1,072 SPX sessions using SPX's own open interest rather than the SPY proxy the literature usually substitutes. Read the post for the result and its caveats; the short version is that the effect popular accounts describe is not what the data supports at index level.

Two related measurements bound it further. Monthly expiration is where pinning should be strongest, and we checked what monthly expiration actually does to the book across 53 opex sessions against 1,024 others — most of the folklore is absent and the two effects that are real are smaller than advertised. And on whether big strikes hold at all, level hold rates measures it directly against a distance-matched control.

Why gex.live does not print a max-pain number

Because a level we cannot verify does not go on the chart. The levels this site does show — the flip, call resistance, put support, the hold band — are each backed by a measurement on the free archive, and each is published with what it fails to do as well as what it does. Max pain has not cleared that bar.